Field of the Invention
The present invention relates to a wireless communication system, and more particularly, to a method of transmitting a channel state information and an apparatus therefor.
Discussion of the Related Art
An antenna system utilizing an AAS (active antenna system) is about to be introduced after LTE Rel-12. Since the AAS is configured by an active antenna that each antenna includes an active circuit, the AAS is expected as a technology capable of more efficiently reducing interference and performing beamforming by changing an antenna pattern according to a situation. If the AAS is constructed in 2 dimensions (2D-AAS), it is able to more actively change a transmission beam according to a location of a receiving end in a manner of more efficiently adjusting a main lobe of an antenna in 3 dimensions in the aspect of an antenna pattern. It is anticipated that the 2D-AAS will construct a plurality of antenna systems by arranging antennas in horizontal direction and vertical direction.